A First inventory of the from Juan de Nova (Iles Eparses, France) in the Mozambique Channel, South Western Indian Ocean. Thierry Mulochau, Chantal Conand, Sabine Stöhr, Marc Eléaume, Pascale Chabanet

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Thierry Mulochau, Chantal Conand, Sabine Stöhr, Marc Eléaume, Pascale Chabanet. A First inven- tory of the echinoderms from Juan de Nova (Iles Eparses, France) in the Mozambique Channel, South Western Indian Ocean.. Western Indian Ocean Journal of Marine Science, Western Indian Ocean Marine Science Association, 2015, 13 (1), pp.23–30. ￿hal-01306709￿

HAL Id: hal-01306709 https://hal.univ-reunion.fr/hal-01306709 Submitted on 26 Apr 2016

HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A First Inventory of Echinodermata at Juan de Nova (Iles Eparses, France) in the Mozambique Channel T. Mulochau1, C. Conand2,3, S. Stöhr4, M. Eleaume3 and P. Chabanet5

1BIORECIF, 3 ter rue de l’Albatros 97434 La Réunion, France ; 2Muséum Histoire Naturelle, 43 rue Cuvier, 75005 Paris, France ; 3UMR Entropie, Université de La Réunion, 97715 Saint-Denis, La Réunion, France ; 4Swedish Museum of Natural History, Department of Zoology, PO Box 50007, 10405 Stockholm, Sweden; 5UMR Entropie, Labex corail, Institut de Recherche pour le Développement, CS 41095, 97495 Ste Clotilde, La Réunion, France.

Keywords: Echinodermata, diversity, reef flats, reef slopes, lagoon, Juan de Nova

Abstract — Juan de Nova is one of the scattered islands known as Iles Eparses in the Mozambique Channel (Western Indian Ocean). Historically, they have been isolated from many anthropogenic influences which makes them ideal areas to study biodiversity for comparison with areas that are heavily impacted by urbanization and fishing. The programme BioReCie (Biodiversity, Resources and Conservation of Eparses Islands) undertook inventories of several marine groups, including echinoderms, which had hitherto not been assessed in Juan de Nova. A multidisciplinary team surveyed the reef slopes of the island using SCUBA to a depth of 25 m as well as the reef flats at low tide, collecting specimens and taking photos for identification. Sixty species were found, with 51 occurring on the reef flats and in the lagoon and 22 on the reef slopes, comprising 21 species of Holothuroidea, 16 Ophiuroidea, 10 Echinoidea, 7 Asteroidea, and 6 Crinoidea. Commercial species of Holothuroidea, some of which are classified as endangered in the IUCN red list, i.e. ananas and nobilis, were present on the reef flats, reef slopes and in the lagoon of the island, indicating the value that protection has on biodiversity.

INTRODUCTION

Juan de Nova is one of the Iles Eparses district of Terres Australes et Antarctiques (French Scattered Islands) which include Françaises (Territory of the French Southern Tromelin, Glorieuses, Bassas da India and and Antarctic Lands). Juan de Nova is located Europa around Madagascar in the south-west in the Mozambique Channel (17°03’16”S; Indian Ocean. Collectively, these islands, 42°43’30”E), 150 km from the west coast of which have an EEZ (Exclusive Economic Madagascar and 285 km from the East African Zone) of approximately 650 000 km2, have coast (Fig. 1). The island is 5.48 km2 in area been governed as a strict Nature Reserve and its coral reefs are 206.69 km2 in extent, under statutes promulgated in 1975 (Gabrié, comprising 163.22 km2 of reef flats and lagoon 1998) and 2007, and constitute the fifth and 43.47 km2 of barrier reef (Andréfouët et

Corresponding author: TM Email: [email protected] Figure 1. Map of the south-west Indian Ocean with the location of Juan de Nova. al., 2009). The EEZ around Juan de Nova is Scientific studies within protected 61 050 km2 in area. A detailed presentation areas in the Indo-Pacific region that are on the island covering its geomorphology and not influenced by serious anthropogenic geopolitical and natural history is presented perturbation increase our knowledge on by Caceres (2003). marine biodiversity, including echinoderms, A survey of the island was undertaken and more particularly on commercially during the BioReCie (Biodiversity, Resources harvested holothurians (Conand et al., 2008; and Conservation of Eparses islands) FAO, 2013; Purcell et al., 2013; Eriksson et programme to map its reef areas and prepare al., 2015). The aim of this study was thus to inventories of several marine taxa for compile the first inventory of echinoderms of management purposes (Chabanet et al., 2012, Juan de Nova. 2013, 2014). Information on echinoderm diversity in the Iles Eparses has hitherto METHODS been very scarce (Vergonzanne, 1977; Mulochau & Conand, 2008) and inventories Fieldwork was conducted during 7-17 on the echinoderms were thus undertaken and December 2013 at Juan de Nova. An presented for Europa (Conand et al., 2013a) echinoderm species inventory was undertaken and on the holothurians for the Glorieuses using an underwater visual census method (Conand et al., 2013b) through the BioReCie (UVC) during SCUBA dives around the island programme. at depths of 3-25 m, except on the reef flats where snorkeling was more efficient at depths echinoderms on the reef surface, in cavities, of 0-3 m. The UVC method entailed a diver under rubble blocks that could be overturned, randomly swimming for a period of 50 minutes and in the sand. in the designated area. Most echinoderms Indices of occurrence of each species were were photographed but were collected when calculated as the number of sites where they identification in situ was not possible, which were present in total and within the two main was found to be the case particularly for the habitat types, viz. the reef flat and lagoons Ophiuroidea and Crinoidea. A total of 25 (rf), and outer reef slope (rs), divided by the sites were sampled around the island, 19 on total number of sites sampled in each habitat the reef flat and on reef patches in the lagoon, type. Taxonomic classification followed the and six on the outer slopes (Fig. 2; Table 1). World Register of Marine Species (Boxshall A total of 300 hours were spent searching for et al., 2014).

Table 1. Site codes, geomorphology, date sampled, coordinates and depth of sites sampled at Juan de Nova in 2013. Site code Reef geomorphology Date Lattitude Longitude Depth (m) 2 Reef flat 08/12/2013 -17.06136 42.71416 0.2 3 Reef flat 09/12/2013 -17.07019 42.71046 0.5 8 Reef flat 12/12/2013 -17.05806 42.69461 0.5 15 Reef flat 15/12/2013 -17.04192 42.71683 1 17 Reef flat 16/12/2013 -17.04783 42.68040 1 20 Lagoonal reef patch 07/12/2013 -17.03259 42.73574 10 25 Lagoonal reef patch 10/12/2013 -16.95350 42.75982 15-18 27 Outer reef slope 11/12/2013 -17.08177 42.72536 13-16 28 Lagoonal reef patch 12/12/2013 -17.01960 42.68127 14 29 Outer reef slope 12/12/2013 -17.05418 42.67435 16-18 30 Lagoonal reef patch 13/12/2013 -16.96562 42.69472 16 31 Lagoonal reef patch 13/12/2013 -16.94298 42.70940 18-19 33 Outer reef slope 14/12/2013 -17.01507 42.65688 20-22 34 Subtidal reef flat 15/12/2013 -17.01076 42.80413 17 35 Outer reef slope 15/12/2013 -17.07472 42.76651 14-20 36 Reef flat 16/12/2013 -17.03337 42.72390 1 37 Reef flat 16/12/2013 -17.03573 42.68453 2 38 Lagoonal reef patch 17/12/2013 -17.03507 42.77117 10 52 Reef flat 07/12/2013 -17.03712 42.72429 3 86 Lagoonal reef patch 09/12/2013 -17.01781 42.71705 15 117 Lagoonal reef patch 11/12/2013 -17.02772 42.72481 16 140 Outer reef slope 14/12/2013 -17.01493 42.65645 28 144 Reef flat 14/12/2013 -17.02939 42.68913 3 165 Reef flat 15/12/2013 -17.05728 42.77669 2 196 Lagoonal reef patch 17/12/2013 -17.03056 42.75651 10 (modified from Andrefouët et al. 2009)

Figure 2. Sampling sites surveyed at Juan de Nova in 2013.

RESULTS

Sixty echinoderm species were found, with 51 CLASS HOLOTHUROIDEA occurring on the reef flats and in the lagoon A total of 21 species of Holothuroidea were and 22 on the reef slopes (Table 2). Only a found at Juan de Nova (Table 3). The species single echinoderm species was found at some stations (8, 15 and 36) which were all with the highest occurrence was Holothuria on the reef flats. Stations 86 and 30 located atra (0.48), which was found at ten sites on on lagoonal patch reef yielded the highest reef flats and lagoonal reef patch and two sites species richness with 17 and 16 echinoderm on the outer slopes. Bohadschia subrubra species. A mean of 8.5 echinoderm species (0.42) were also frequently sampled on was sampled per site on the reef slopes and reef flats and lagoonal reef patch, as were 7.3 on the reef flats and lagoonal reef patches. Bohadschia atra, Holothuria nobilis and Stichopus chloronotus each at an occurrence Table 2. Echinoderm classes sampled at Juan de of 0.37. Thelenota ananas was the most Nova in 2013. abundant (0.83) species on the outer slopes Class Reef flat Outer Total but Actinopyga cf. obesa was also frequently and lagoon reef slope sampled in this habitat (0.50). Holothuroidea 20 10 21 We found at least one species of Ophiuroidea 14 4 16 Holothuroidea at each station. Site 52, in Echinoidea 8 5 10 the lagoon, had seven species, registering Asteroidea 7 2 7 the greatest diversity for this class. Six species of Holothuroidea were recorded Crinoidea 2 4 6 sites 17 and 86 in the lagoon, and site 140 Total 51 22 60 on the outer slope. Table 3. Occurrence of the Holothuroidea observed Table 4. Occurrence of the Ophiuroidea observed at at Juan de Nova with the total number of sites at Juan de Nova with the total number of sites at which which species occurred, total occurrences (25 species occurred, total occurrences (25 sites), occurrence sites), occurrence on the reef flats and lagoonal reef on the reef flats and lagoonal reef patches (rf; 19 sites) patches (rf; 19 sites) and occurrence on the outer and occurrence on the outer reef slopes (os; 6 sites). reef slopes (os; 6 sites). No. of total occ. occ. Occurrence sites/sp occ. rf os Species N of Total rf os Macrophiothrix longipeda 5 0.2 0.26 0 sites Ophiocoma erinaceus 3 0.12 0.16 0 Holothuria nobilis 7 0.28 0.37 0 Ophiocoma (breviturma) brevipes 6 0.24 0.26 0.17 Thelenota ananas 10 0.4 0.26 0.83 Ophiomastix venosa 1 0.04 0.05 0 Stichopus chloronotus 10 0.4 0.37 0.33 Ophiocoma cynthiae 3 0.12 0.16 0 Holothuria atra 12 0.48 0.53 0.33 Ophionereis dubia 1 0.04 0 0.17 Bohadschia subrubra 10 0.4 0.42 0.33 Ophiarachnella gorgonia 1 0.04 0.05 0 Bohadschia atra 9 0.36 0.37 0.33 Ophionereis sp. 1 0.04 0.05 0 Ophionereis porrecta 3 0.12 0.1 0.17 Pearsonothuria graeffei 5 0.2 0.16 0.33 Ophiopeza fallax 1 0.04 0 0.17 Stichopus herrmanni 1 0.04 0.05 0 Ophiactis savignyi 1 0.04 0.05 0 Holothuria impatiens 2 0.08 0.1 0 cf. Ophiactis 1 0.04 0.05 0 Actinopyga cf.miliaris 3 0.12 0.1 0.17 cf. Ophiolepis (juv) 1 0.04 0.05 0 Actinopyga cf.obesa 5 0.2 0.05 0.5 Ophiura cf. kinbergi 1 0.04 0.05 0 Ophiocoma pusilla 1 0.04 0.05 0 Actinopyga mauritiana 4 0.16 0.21 0 cf. Ophiothela 1 0.04 0.05 0 Holothuria hilla 2 0.08 0.1 0 Holothuria pardalis 1 0.04 0.05 0 CLASS ASTEROIDEA Actinopyga echinites 1 0.04 0.05 0 Thelenota anax 1 0.04 0.05 0 Seven species of Asteroidea were sampled (Table 5), two of which were recorded with the Holothuria fuscogilva 2 0.08 0.05 0.17 highest occurrence on the reef flats and in the Holothuria difficilis 1 0.04 0.05 0 lagoon: Culcita schmideliana (0.20) and Linckia Holothuria sp. 1 1 0.04 0.05 0 laevigata (0.20). Two species (Neoferdina offreti Holothuria sp. 2 1 0.04 0 0.17 and Acanthaster planci) found in the lagoon Holothuria cf.fuscocinerea 1 0.04 0.05 0 were also sampled on the outer slopes. Site 86 has the highest species richness of Asteroidea CLASS OPHIUROIDEA with three species being recorded. A total of 16 species of Ophiuroidea were Table 5. Occurrence of the Asreroidea observed sampled (Table 4) but not all were identified at Juan de Nova with the total number of sites at due to difficulties in their collection. Two which species occurred, total occurrences (25 species were recorded with the highest sites), occurrence on the reef flats and lagoonal reef patches (rf; 19 sites) and occurrence on the outer occurrence on the reef flats and lagoonal reef reef slopes (os; 6 sites). patches: Ophiocoma (Breviturma) brevipes (0.24) and Macrophiothrix longipeda (0.20). No. of total occ. occ. sites/sp occ. rf os Ophiocoma erinaceus and O. cynthiae were Acanthaster planci 4 0.16 0.16 0.17 also regularly observed. Only three species were sampled on the reef slopes, the most Culcita schmideliana 5 0.2 0.26 0 common being Ophionereis porrecta which Linckia laevigata 5 0.2 0.26 0 was also found on the reef flats and in the Asteropsis carinifera 1 0.04 0.05 0 lagoon. Site 30 in the north of the lagoon Neoferdina offreti 3 0.12 0.05 0.33 near the outer slope had the highest species Dactylosaster cf.cylindricus 1 0.04 0.05 0 richness of Ophiuroidea with six species. Linckia multifora 1 0.04 0.05 0 CLASS ECHINOIDEA Table 7. Occurrence of the Crinoidea observed at Juan de Nova with the total number of sites at Ten species of Echinoidea were sampled which species occurred, total occurrences (25 (Table 6), two of which (Echinostrephus sites), occurrence on the reef flats and lagoonal reef molaris and Echinothrix diadema) had the patches (rf; 19 sites) and occurrence on the outer highest abundance on the reef flats and reef slopes (os; 6 sites). lagoonal reef patches. Echinostrephus molaris No. of total occ. occ. was frequently sampled at 14 of the 25 sites sites/sp occ. rf os and, on the outer slopes, was always found associated with four other species: Echinothrix Stephanometra indica 1 0.04 0 0.17 calamaris, Eucidaria metularia, Prionocidaris Antedonidae 1 0.04 0 0.17 cf. pistillaris and Heterocentrotus mammilatus. Tropiometra carinata 1 0.04 0.05 0 Site 86 had the highest species richness of Cenometra bella 1 0.04 0 0.17 Echinoidea with three species being recorded. Crinoidea sp. 1 1 0.04 0.05 0 Crinoidea sp. 2 1 0.04 0 0.17 Table 6. Occurrence of the Echinoidea observed at Juan de Nova with the total number of sites at which species occurred, total occurrences (25 sites), occurrence on the study was a first inventory of echinoderms the reef flats and lagoonal reef patches (rf; 19 sites) and related to reef geomorphology within the occurrence on the outer reef slopes (os; 6 sites). broader context of the reef slopes and the reef No. of total occ. occ. flats with associated lagoonal patch reefs. sites/sp occ. rf os The occurrence of the Holothuroidea revealed that commercially valuable species Echinothrix calamaris 9 0.36 0.42 0.17 such as Thelenota ananas, Bohadschia atra, B. Echinothrix diadema 2 0.08 0.1 0 subrubra, and Holothuria nobilis were present Echinostrephus molaris 14 0.56 0.37 1 right around the island. Several species of Echinometra mathaei 1 0.04 0.05 0 Holothuroidea are listed on the IUCN list as Stomopneustes variolaris 2 0.08 0.1 0 endangered or vulnerable (Conand et al., 2014) Plococidaris verticillata 1 0.04 0.05 0 and the strict Nature Reserve within which Eucidaris metularia 3 0.12 0.1 0.17 Juan de Nova lies represents an important area for the protection of this marine resource. A Prionocidaris cf. pistillaris 1 0.04 0 0.17 further survey will be necessary to quantify the Heterocentrotus mammillatus 1 0.04 0 0.17 Holothuroidea in the protected areas of the Les Metalia spatagus 1 0.04 0.05 0 Eparses to compare their abundance with other areas that are highly fished (Conand, 2008; CLASS CRINOIDEA Purcell et al., 2012, 2013; FAO, 2013; Muthiga et al., 2014; Eriksson et al., 2015). The Six species of Crinoidea were sampled (Table of several species still needs more 7) with site 34 having six species, the highest investigation and samples of tegument will number of crinoid species. be needed for their identification based on the DISCUSSION spicules. DNA barcoding employing the COI gene may help to separate morphologically A total of 60 species of echinoderms related species as Actinopyga miliaris, A. obesa were recorded at Juan de Nova, a lower and, perhaps a third morphotype. number than that recorded at Glorieuses (67 Ophiuroidea are common on the reef flats species; Mulochau & Conand, 2008, 2013; and in the lagoon, whereas only two species Vergonzanne, 1977) but higher than Europa were found on the reef slopes. Nevertheless, where only 39 species were found (Conand some Ophiuroidea are known to be negatively et al., 2013a). Indices of their abundance are phototactic (Fell, 1966) and hide in the provided but the data were qualitative and not crevices of coral reefs during the day, making amenable to further analysis; the objective of them difficult to find. Amongst the Asteroidea, outbreaks of the Centre National pour la Recherche (INEE- crown-of-thorns sea star Acanthaster planci CNRS), the Institut National des Sciences de remain one of the most significant biological l’Univers (INSU), the Institut de Recherche disturbances on tropical coral reefs (Baird, pour le Developpement (IRD), the Fondation 2013). We did not encounter a high abundance pour la Recherche sur la Biodiversité (FRB), of A. planci, although this species was present the Agence des Aires Marines Protégées (AAMP) at Juan de Nova. Linckia laevigata and C. and the Véolia Environment Foundation. We are schmideliana are two large-sized species of thankful to all the participants in BioReCie Juan Asteroidea that have frequently been found de Nova (P. Chabanet – the expedition leader, S. at Juan de Nova, Europa and the Glorieuses Andrefouët, L. Bigot, C. Bourmaud, J-F Dupied, Islands (Conand et al., 2013a & 2013b). P. Durville, N. Gravier-Bonnet, S. Lauriol, H. Among the Echinoidea, Echinostrephus Megalon, L. Mattio, J.B. Nicet, C. Russo, A. and molaris was abundant at all the sites on the N. Tisné, S. Turay and M. Zub) for their assistance, outer reef slopes and was the echinoderm observations and photos. The assistance of E. with the highest occurrence. This concurs with Boissin in the identification of the ophiuroids, our previous findings at the other Iles Eparses C. Mah in the identification of the asteroids and (Mulochau & Conand, 2008; Conand et al., 2013a). J.B. Nicet for the production of Figure 2 was Crinoidea, like the Ophiuroidea, have the appreciated. The comments of the anonymous ability to hide in crevices of a coral reef during referees have helped to improve the manuscript. the day to protect themselves from predators. DNA barcoding of two species encountered, References Stephanometra indica and Tropiometra carinata, has revealed that their genetic diversity is Andréfouët S, Chagnaud N, Kranenburg CJ higher than expected (Hemery, pers com). (2009) Atlas of Western Indian Ocean The specimens from Reunion Island and those coral reefs. Centre IRD de Nouméa, collected elsewhere in the Mozambique Channel, New-Caledonia, 157 pp e.g. the Glorieuses Islands and Madagascar have Baird AH, Pratchett MS, Hoey AS, Herdiana Y, revealed significant genetic differences (Torrence Campbell SJ (2013) Acanthaster planci et al., 2012; Hemery et al., 2013). Stephanometra is a major cause of coral mortality in Indonesia. Coral reefs 32: 803-812 indica and T. carinata could, therefore, constitute complexes of several species. Boxshall GA, Mees J, Costello MJ, Hernandez F, Gofas S, et al. (2014) World Register More field-work is needed to improve this of Marine Species. Available at http:// first inventory for further comparison with other www.marinespecies.org at VLIZ. Date surveys in the south-western Indian Ocean. accessed 2014. Sampling at night might produce a more complete Caceres S (2003) Etude préalable pour le inventory, especially for the Ophiuroidea, small classement en réserve naturelle des îles species of Asteroidea and the Crinoidea. Further Eparses. Mémoire de DESS Sciences studies will also improve our understanding of et Gestion de l’Environnement their ecological role on the reefs of Juan de Nova tropical. DIREN Réunion, Laboratoire in terms of their distribution, community structure d'écologie marine de l'Université de La and habitat utilization. Réunion, Saint-Denis, 195 pp Chabanet P, Bigot L, Nicet J-B, Andrefouët S, Acknowledgements – We would like to thank Bourmaud AF, Conand C, Durville P, the administration of the TAAF (Terres Australes Fricke R, Gravier-Bonnet N, Le Pape O, et Antarctiques Françaises) for research permits Mulochau T, Magalon H, Obura D, Poupin and financial support, the ‘Forces Armées de la J, Quod J-P, Tessier E, Zubia M (2012) Zone Sud ocean Indien’ (FAZSOI) for logistical Multi-disciplinary approaches for coral reef support. Financial support for the expeditions management in Eparses Islands (SWIO). to Juan de Nova island was also provided by 12th International Coral Reef Symposium, the Institut Ecologie et Environnement du Cairns, Australia, 9-13 July 2012, abstract Chabanet P, Bigot L, Bourmaud A-F, Cavailles FAO (2013) Report on the FAO Workshop on G, Durville P, Gravier-Bonnet N, fisheries: An ecosystem Magalon H, Mattio L, Mulochau T, approach to management in the Indian Nicet J-B, Obura D, Poupin J, Zubia M Ocean (SCEAM Indian Ocean). FAO (2013) Assessing coral reef biodiversity Fisheries and Aquaculture Report No. at Glorieuses islands Marine Park 1038, 92 pp (Scattered Islands, SW Indian Ocean) Fell HB (1966) The ecology of ophiurids. with identification for priority zones In: Boolootian RA (ed) Physiology for conservation. 8th Western Indian of Echinodermata. John Wiley, New Ocean Marine Science Association York, pp 129-145 Conference, Maputo, Mozambique, 28 October – 2 November 2013, abstract Gabrié C. 1998. L’état des récifs coralliens en Chabanet P, Andrefouet S, Bigot L, Bourmaud France Outre-Mer. ICRI. Doc. Secrétariat A-F, Conand C, Durville P, Fricke R, d’Etat à l’Outre-Mer et Ministère de Gravier-Bonnet N, Mattio L, Mulochau l’Aménagement du Territoire et de T, Magalon H, Nicet J-B, Obura D, l’Environnement, 136 pp Poupin J, Russo C, Tessier E, Zubia Hemery LG, Eléaume M, Roux M, Améziane N M (2014) Biodiversité, ressources et (2013) High resolution crinoid phyletic conservation des récifs coralliens des inter-relationships: A preliminary study. Iles Eparses. Colloque Iles Eparses, Cahiers de Biologie Marine 54: 511-523 Campus Gérard-MEGIE du CNRS, Paris, 28-29 April 2014, abstract Mulochau T, Conand C (2008) Holothurians and other echinoderms of the Conand C (2008) Population status, Glorieuses Islands (Scattered Islands fisheries and trade of sea cucumbers of the Indian Ocean). SPC Bêche-de- in Africa and Indian Ocean In: Toral- mer Information Bulletin 28: 34-39 Granda V, Lovatelli A, Vasconcellos M (eds) Sea cucumbers. A global Muthiga N, Conand C (2014) Sea cucumbers review on fishery and trade. FAO in the western Indian Ocean: Improving Fisheries Technical Paper No. 516. management of an important but poorly Rome, FAO, pp 153-205 understood resource. WIOMSA Book Conand C, Stöhr S, Eléaume M, Magalon H, Series No. 14, 74 pp Chabanet P (2013a) The echinoderm Purcell SW, Mercier A, Conand C, Hamel J-F, fauna of Europa, Eparses Island, Toral-Ganda V, Lovatelli A, Uthicke (Scattered Islands) in the Mozambique S (2013) Sea cucumber fisheries: Channel (South Western Indian Ocean). Global analysis of stocks, management Cahiers de Biologie Marine 54: 499-504 measures and drivers of overfishing. Conand C, Mulochau T, Chabanet P (2013b) Fish and Fisheries 14: 34–59 Holothurian (Echinodermata) diversity Torrence KG, Correia MD, Hoffman EA in the Glorieuses Archipelago (Eparses (2012) Divergent sympatric lineages of Islands, France, Mozambique Channel). the Atlantic and Indian Ocean crinoid Western Indian Ocean Journal Marine Tropiometra carinata. Invertebrate Science 12: 71-78 Biology 131: 355-365 Conand C, Polidoro BA, Mercier A, Gamboa RU, Hamel J-F, Purcell SW (2014) Vergonzanne G (1977) Etude sur les The IUCN Red List assessment of mollusques et les echinodermes aspidochirotid sea cucumbers and its récifaux des Iles Glorieuses (nord- implications. Bêche-de-mer Information ouest de Madagascar). Bionomie Bulletin, 34: 3-7 et évaluations quantitatives. Thèse de 3ème cycle d’Océanographie, Eriksson H, Conand C, Lovatelli A, Muthiga Université de Bretagne occidentale, N, Purcell S (2015) Governance Brest, 159 pp structures and sustainability in Indian Ocean sea cucumber fisheries. Marine Policy 56: 16–22